Cast Iron Brake Drums -OT video & thoughts.....

BRENT in 10-uh-C

BRENT in 10-uh-C

Well-known member
There has been a long-standing discussion here about Model-A cast iron brake drums of whether to use the US manufactured nodular iron drums or whether the off-shore manufactured gray cast iron are just as good. FWIW, I only use the nodular iron drums, but feel free to use whatever you feel comfortable with using on your Model-A.

With that said, a well respected YouTube content provider just uploaded this video regarding machine work on reproduction 1914 American Underslung brake drums. In this video he discusses having a conversation with another well-known foundryman named Clarke Easterling with Windy Hill Foundry down in Mississippi. For those interested, watch this video ( https://youtu.be/0lDP0Ty8ioo?si=mcnDzormOA7b4pd7 ) sometime, and then post some thoughts based on Keith's experience with those drums and the advice Clarke gives about what he uses and why.
 
My understanding is that the Randy Gross supplied drums are gray iron and the Snyder's/Bratton's drums are nodular iron. Mel Gross was on here about ten years ago saying that he had complete confidence in the gray iron drums. Since Snyder's doesn't supply hub-drum assemblies, it sounded to me like the nodular drums might be slightly more forgiving if people are swaging the studs into them who don't do that operation a dozen times a day. I'm speculating on that though.
 
Colin, did you pickup on the conversation Keith had with Clarke when he said that OE manufacturers install a metal plate in that portion of a brake drum (-even when using the nodular iron) for added strength?

While a Model-A drum is riveted to a flange on the hub, most modern vehicles with brake drums also use a flange on the axle. Apparently in addition to that metal plate that is inserted into the casting, they have the axle flange for more rigidity and support.

So IYO, is this metal plate important, ...especially in a gray-iron application??
 
It's been hard finding good information about this. Brake drums are made from a variety of materials, including aluminum. The key factor seems to be how much you want the drum to weigh. Pressed steel faces allow the drum to be lighter for the same strength. However, the manufacturing process is more expensive because you have to mate the dissimilar metals.

So my guess is the Model A drums aren't made in the quantities that would justify first engineering and then manufacturing a dual-metal design.

Note that gray iron dissipates heat better than nodular, so designs relying on steel for strength tend to use gray iron.
 
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